Video skips frames while AQ drains to 0

[jbennett]

I'm having a regular problem with video playback using MrMC 2.6.0 on a Fire TV 2. A couple or more times an hour, for a period of a few seconds, video will start stuttering. During this period, codecinfo shows video skipped frames slowly rising (maybe 1-3 per second), and a/v sync rising as high as 15, while audio queue starts draining faster than it's refilled - it "zigzags" its way from a solid 99% all the way down to zero. Once AQ hits zero, playback pauses for a split second and resumes, with everything back to normal.

All other stats (cpu, etc.) look nominal throughout. Device temperature seems fine, barely warm to the touch. Problem has occurred with both MKV and MP4 containers, both H.264 and H.265 video, stereo and multichannel PCM, AC-3 5.1 and DTS 5.1 audio, from multiple file locations (micro SD in USB card reader, micro SD in built-in slot, local uPnP server, and WebDAV connection to Box cloud). I've been running GUI and video at 24p (no vsync) for a while, but I'm pretty sure this also happened at 60p.

Please let me know how to capture a sufficiently "clean" log, if needed (i.e., should I try to catch this as soon as possible after startup, stop and grab log right after it happens, etc.).

Thanks!

[amet]

best is to catch it as soon as possible, to avoid going through thousands of lines of text

http://mrmc.tv/forum/viewtopic.php?f=12&t=373

be sure to enable debug logging

[jbennett]

Well, no better way to fix it than to threaten to log its bad behavior... Just like how your car suddenly stops making that funny noise the moment you take it to a mechanic.

Actually, I'm sure it's due to the fresh reboot I gave it beforehand, but I just got through an entire 100-minute movie without a skipped frame. This leads me to believe it's some kind of cumulative resource issue (memory leak, etc.), but it's nearly 4:30 AM here now, so I'll give the logging another shot with a longer film tomorrow.

[cosmoxl]

I've had this problem too. Workaround for me was to disable passthrough.

[davilla]

There is a random issue under fireOS, sometimes, there is an error releasing a MediaCodec buffer. Unknown cause. the temp fix is a quick seek back.

[jbennett]

There is a random issue under fireOS, sometimes, there is an error releasing a MediaCodec buffer. Unknown cause. the temp fix is a quick seek back.

Hmm, "random" and "unknown cause" never sound very promising for a fix, but this sounds like it's probably the issue I'm having.

I was going to open a separate thread for this, but I also have a consistent problem recovering from pause or seek operations. For instance, downloading subtitles (with automatic pause turned on) will usually cause jerky video and audio dropouts until I stop and resume playback.

Finally, does the debug log simply get overwritten upon startup, or are they rotated so I can retrieve the previous one? I woke up to a black screen, unresponsive to any remote inputs or web client, and had to unplug it. Third time this has happened (always during video playback, one time I witnessed it stuttering first) in the week or so I've had it. Is there any way to access logcat without root or ADB access, or anything else I can retrieve that would be useful to you for crash diagnosis?

Thanks!

[jbennett]

I've had this problem too. Workaround for me was to disable passthrough.

I'll double-check, but I'm pretty sure my problem even happens with PCM or DTS (decoded to PCM) audio, and I only use Dolby passthrough. If disabling passthrough *is* the answer, though, then that itself will kind of suck, differently.

Thanks for the tip, though...

[cosmoxl]

There is a random issue under fireOS, sometimes, there is an error releasing a MediaCodec buffer. Unknown cause. the temp fix is a quick seek back.

Hmm, "random" and "unknown cause" never sound very promising for a fix, but this sounds like it's probably the issue I'm having.

I was going to open a separate thread for this, but I also have a consistent problem recovering from pause or seek operations. For instance, downloading subtitles (with automatic pause turned on) will usually cause jerky video and audio dropouts until I stop and resume playback.

Finally, does the debug log simply get overwritten upon startup, or are they rotated so I can retrieve the previous one? I woke up to a black screen, unresponsive to any remote inputs or web client, and had to unplug it. Third time this has happened (always during video playback, one time I witnessed it stuttering first) in the week or so I've had it. Is there any way to access logcat without root or ADB access, or anything else I can retrieve that would be useful to you for crash diagnosis?

Thanks!

http://forum.mrmc.tv/viewtopic.php?f=12&t=373 last post in that thread shows way to get old log.

https://support.herotalkies.com/support ... on-fire-tv

I followed those directions to get logcat output using ADB. It's pretty easy so not sure why you're opposed to using it.

[davilla]

There is a random issue under fireOS, sometimes, there is an error releasing a MediaCodec buffer. Unknown cause. the temp fix is a quick seek back.

Hmm, "random" and "unknown cause" never sound very promising for a fix, but this sounds like it's probably the issue I'm having.

I was going to open a separate thread for this, but I also have a consistent problem recovering from pause or seek operations. For instance, downloading subtitles (with automatic pause turned on) will usually cause jerky video and audio dropouts until I stop and resume playback.

Finally, does the debug log simply get overwritten upon startup, or are they rotated so I can retrieve the previous one? I woke up to a black screen, unresponsive to any remote inputs or web client, and had to unplug it. Third time this has happened (always during video playback, one time I witnessed it stuttering first) in the week or so I've had it. Is there any way to access logcat without root or ADB access, or anything else I can retrieve that would be useful to you for crash diagnosis?

Thanks!

log gets rotated, mrmc.old.log, see last post in http://mrmc.tv/forum/viewtopic.php?f=12&t=373

"random" and "unknown cause" just makes it harder to hunt. But I like hunting bugs.

[jbennett]

I've had this problem too. Workaround for me was to disable passthrough.

I'll double-check, but I'm pretty sure my problem even happens with PCM or DTS (decoded to PCM) audio, and I only use Dolby passthrough. If disabling passthrough *is* the answer, though, then that itself will kind of suck, differently.

Thanks for the tip, though...

Okay, now I'm wondering if my two problems are actually unrelated. I just confirmed that the reproducible-on-demand problem with jerky video and audio dropouts after pausing or seeking *does* only happen with AC-3 audio, and turning off Dolby Digital passthrough does indeed fix (or rather, work around) it.

However, I know for sure that my similar but spontaneously-occurring problem (described in my initial post) has occurred with other audio formats, even stereo PCM. I'll try to catch it in the act again with one of those files to eliminate Dolby as a variable.